Rotary-hearth furnace



March 10, 193-1.

E. G. DE CORIO LIS ET AL ROTARY HEARTH FURNACE Filed A ril 26. 1929 lNVENTDRS 5.6. 91: (oz/0M; J #0553. /i. 1.119255.

ATTU

Patented Mar. 10, 1931 UNITED STATES PATENT OFFICE nnnns'r' G. 1m comoLIs, JESSE nor mosnn, AND ARNOLD L. nansnn, or TOLEDO, onro,

ASSIGNOBS 'ro summon oomnus'rron conrona'rron, or TOLEDO, 01110, A conrom- I'ION OF NEW YORK Application filed April 26,

i This invention relates to furnaces of the rotary hearth type and has for its object to provide a hearth supporting and drlving mechanism of such construction.'that the hearth, exclusive of suchmechanism, may be removed from the furnace through the top thereof after removing the roof therefrom. Another object is to provide a simple and practical means for protecting the hearth and its supporting and driving mechanism from excessive heat within the furnace. An additional object is to provide a simple and practical means permittirigthe introduction into the furnace chamber through the center of the hearthof a gaseous medium for controlling the. furnace atmosphere. The features of construction whereby the above and other objects are attained will more fully appear from the detailed description taken in connection with the accompanying drawing wherein the preferred furnace construction is illustrated.

Referring to the drawing, the furnace chamber is formed by a cylindrical refractory shell 2 capped by a roof 4 which is surrounded by and set into a ring 6 .having upstanding perforated lugs 8 to permit the roof to be readily lifted and set aside preparatory to removing the hearth from the furnace. Surrounding the furnace is a sheet metal shell 10 which projects below thebottom of the side walls of the chamber. Secured to the shell 10 above its bottom edge is an annular ring 12 on which is supported a plate 14 which in turn forms a support for the walls 2 of the furnace chamber. The middle portion of the plate is supported in any suitable manner as by an annular member 16. The annular member 16 and the bottom edge of the sheet metal shell 10 will of course rest on' a suitable foundation not shown.

Mounted on the bottom plate 14 is an annular member 18 on which is rotatably mounted a ring gear 20 which is driven by a worm 22 supported in a bracket 24 secured to the annular member 18. Mounted on the ring gear is an annular stool or member 26 the hearth being removably mounted on this 1 member.

The hearth is generally indicated at 28 and BOTARY-HEARTH FURNACE- 1929. Serial No. 358,252.

comprises a refractory bed of appropriate thickness. The foundationiof t e hearth comprises a relatively shallow sheet-metal chamber 30 through which cooling fluid may be circulated. This chamber is prevented from collapsing by interiorly positioned radially extending webs 32 which webs also define radial channels for the cooling fluid, the webs terminating short of the peripheral walls of the chamber whereby there is formed an annular flow path within the casing and the webs also terminate short of the center of the casing to provide for the distribution of the cooling fluid. Cooling fluid is supplied to the chamber 30 by a conduit which includes a swivel joint 36 and a pipe 34 which extends through an opening in the bottom plate 14 of the furnace and leads to a suitable source of supply of said fluid.

Depending from the bottom of the hearthcooling chamber or container 30 adjacent to which extends into an annular trough 40 adapted to contain liquid and thus form a liquid seal. The level of the liquid is governcd by the overflow pipe 42 which extends from the bottom of the trou h to a point exteriorally of the furnace, t e outlet of the pipe being above the bottom. of the trough as will be readily understood. The cooling fluid introduced into the hearth cooling chamber 30 is preferably water which water leaves the chamber 30 through an overflow pipe 44 having its inlet extending into a recess formed in the top of said chamber thereby preventing drainage ofwater from the chamber unless it is completely full.

The pipe 44 is referably in the same vertical. plane as the ange 38.and to that end the flange is split to permit the pipe to project into the trough. A layer of 011 preferably floats on the water in the trough to prevent vaporization thereof by the heat of the furnace. The trough is supported on an annular plate. 46 which rests on the bottom plate 14 --of the furnace, bracing webs or standards 48 being also provided.

That portion of the furnace chamber below the floor of the hearth is of somewhat greater diameter than the heating chamber proper above the hearth and the diameter of the hearth is such as to provide ample clearance with the surrounding walls of the fur.- nace chamber. Scales and dbris fronl the hearth .may therefore drop to the bottom of the furnace chamber as indicated by refer ence numeral 50.. A Suitable cleaning opening not shown may be of course provided for removing the scale.

The hearth need not be secured to its support 26 by mechanical means nor. need the support 26 be mechanically secured to the ring gear. To'facilitate centering the hearth on its support there is provided a plurality of depending inwardly turned fingers 52. It will now be readily appreciated that after the roof of the furnace has been removed it is a simple matter to remove the hearth from the furnace chamber it being merely necessary to lift it from its annular support 26 in any suitable manner as by engaging it from below by hooks adaptedto be passed between the sides of the hearth and the furnace chamber walls.

The hearth is provided with an upstanding central post 54 which just clears the furnace roof thereby imparting annular form to the heating chamber. This chamber is fired by suitable gas burners which are preferably of a type adapted to burn explosive gaseous mixtures of fuel gas and air. A burner of this type is indicated at 56 the same firing into a combustion tunnel 58. Work to be heated is entered into the heating chamber.

and removed therefrom through a suitable opening 60 formed in the wall of the furnace chamber. 62 indicates a shield in front of said opening tending to prevent furnace gases from reachi'n r the operator.

It is also desirab e to form a curtain of air in front of the opening 60 as by means of a tube 64 having a slot or a series of jet openings 6 6 in its up. er surface. This curtain of air not only ten s to prevent hot gases from reaching t e operator but also materially prevents the in-flow of air into the heating chamber.

The furnace is also provided with means for introducing a gaseous medium into the heating chamber to produce any desired furnace atmosphere. For this purpose a passage is provided through the center ofthe hearth the passage terminatingin radial 'discharge passages 68uformed in the post54; In gas tighboonnection with the lower end of the heartlypassage is a conduit 70 which preferably extends through the water supply con dnit to swivel'connection Z,2 \which is con- Hctedwith a source of shpply wf-the gaseous medium. i

It is preferred that the conduits; which supply the "cooling water and-gaseous, medium be soconst'ructed and arranged that b simply disconnecting the'supply pipes which connect with-{the swivel connections 36 and 72 the re-- ,within the chamber, of means for supporting said hearth comprising an annular member, a ring gear on which said member 1s supported, an annular member formm g a support for said gear, and an annular trough cooperating with the hearth to form a seal for preventing furnace gases, from reaching the hearth supporting means.

2. The combination with a rotary disk-type hearth and an upright heating chamber sur rounding said hearth, of a vertically unconfined stool on which the hearth is removably supported, a ring gear on which the stool is removably supported, an annular bearing on which the ring gear is rotatably and removably supported, and means for rotating said ear. 3. The combination with a rotary hearth and an upright heatin chamber surrounding said hearth, of a stood on which the hearth is supported, a rotatable support on which said stool is mounted, an upright casing surrounding said support and stool, means cooperating with said casing and hearth to form a seal against the flow of gases between said chamber and casing, a fluid container formingthe bottom of said hearth, and means for supplying cooling. medium to said container.

4. The combination with a rotary hearth and an upright chamber surrounding said hearth, of a ring gear disposed below the hearth in spaced relation therewith, a fixed mounted, a stool supported on said gear and forming a support for said hearth. a fluid container forming the bottom of said hearth. means for introducing cooling fluid into said container at a point in the axis of the hearth, an annular trough below the hearth into which the spent cooling fluid may flow from the container, and a casing surrounding said stool and support and forming a support for said trough 5. T he combination with an upright heating chamber, of a metal base on which said chamber-is supported, a ring gear operatively supported on said base for rotation about a vertical axis, a stool removably supported on said gear for rotation therewith, a hearth removably-supportedxon said stool for rota tion'the'rewith, and means cooperating] with the bottom of' said hearthand'said'base for shielding" the hearth supporting mechanism from heating chamber gases.

,6. The combination with a, rotary disk-type v the hearth comprising a relatively fixed annular bearing at the bottom of said chamber, a ring gear rotatably supported on and vertically removable from said bearing, means 5 for removably supporting said hearth on said gear, and means for rotating said gear whereby to rotate said hearth. I

In testimony whereof we afiix our signatures. 'l 10 ERNEST G. DE GORIOLIS.

JESSE ROY MOSER. ARNOLD L. LARSEN. 

